NMR STUDIES OF METALLOTHIONEIN STRUCTURE AND REACTIVITY

金属硫蛋白结构和反应性的核磁共振研究

• 批准号: 3251868
• 负责人: JAMES D OTVOS
• 金额: $ 8.71万
• 依托单位: UNIVERSITY OF WISCONSIN MILWAUKEE
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-04-01 至 1989-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3251868
• 关键词: cadmium; chemical structure function; copper; detoxification; ligands; metal metabolism; metal poisoning; metallothionein; nuclear magnetic resonance spectroscopy; radiotracer; zinc

This proposal sets forth an integrated series of chemical and structural studies to elucidate biologically relevant structure-reactivity correlations of the metal binding protein, metallothionein (MT). This protein is a normal constituent of mammalian tissues and it or related structures are found in a wide vartiety of non-mammalian species. It is the principal intracellular binding site for the environmentally important, toxic heavy metal Cd and is thought to provide the means for its detoxification. A central role has also been proposed for MT in the metabolism of the essential metals Zn and Cu. Depending on the physiological status of the organism in which it is found, the protein can contain more than one type of metal and, in fact, is most often found in a mixed-metal state. The overall goal of the proposed research is to rationalize on the basis of in vitro metal exchange reactions how these mixed metal MTs are formed in vivo and to determine the structural and chemical conseqeueces of shared occupancy of the metal-thiolate clusters by different metals. The structural probes to be used are 113Cd and 1H NMR and they will be interactively employed to provide complementary information regarding the environments of the metals at each of the seven binding sites and the protein structure surrounding these sites. The following specific goals will be pursued: (1) to determine structural diffrences that exist between MT isoproteins and between the two metal-thiolate clusters as a function of the metal bound, (2) to characterize the binding of Cd to apoMT, (3) to investigate the kinetics and mechanisms of reactions which produce mixed Cd,ZnMTs, (4) to characterize the products of in vitro reactions which produce mixed Cu,ZnMTs and Cu,CdMTs, and (5) to assess the biological relevance of these reactions by comparing their products to those of native rabbit liver Cu,ZnMT.

这项建议提出了一系列综合的化学和结构 阐明生物相关结构-反应性的研究 金属结合蛋白、金属硫蛋白(MT)的相关性。这 蛋白质是哺乳动物组织的正常成分，它或与之相关 结构广泛存在于各种非哺乳动物物种中。它是 对环境具有重要意义的主要细胞内结合部位， 有毒的重金属Cd，被认为提供了 解毒。也有人提议让MT在 必需金属元素锌和铜的代谢。取决于 发现这种蛋白质的生物体的生理状态，这种蛋白质可以 含有不止一种类型的金属，事实上，最常见的是在 混合金属状态。拟议研究的总体目标是 在体外金属交换反应的基础上合理化这些 混合金属MTs是在体内形成的，并确定了结构和 金属硫酸盐簇合物共占位的化学结构 不同的金属。要使用的结构探针是~(113)Cd和~1H核磁共振 他们将被交互使用，以提供互补的 关于七种金属中每一种的环境信息 结合部位和这些部位周围的蛋白质结构。这个 将追求以下具体目标：(1)确定结构 MT同工蛋白之间以及两者之间存在的差异 作为金属结合的函数的金属硫酸盐簇合物，(2)至 表征Cd与apoMT的结合，(3)动力学研究 和产生混合Cd，ZnMTs的反应机理，(4)到 对产生混合反应的体外反应产物进行表征 铜、锌金属氧化物和铜、镉金属氧化物，以及(5)评估它们的生物学相关性 它们的反应产物与天然兔肝的比较 铜、锌金属氧化物。